EP 1342923 A1 20030910 - CHANGE-OVER VALVE FOR BOOM CYLINDER OF EXCAVATING/SLEWING WORK TRUCK
Title (en)
CHANGE-OVER VALVE FOR BOOM CYLINDER OF EXCAVATING/SLEWING WORK TRUCK
Title (de)
UMSCHALTVENTIL FÜR AUSLEGERZYLINDER EINES BAGGER-/SCHWENKARBEITSWAGENS
Title (fr)
VALVE DE SELECTION POUR CYLINDRE DE FLECHE DE VEHICULE EXCAVATEUR/PIVOTANT
Publication
Application
Priority
- JP 0110453 W 20011129
- JP 2000375860 A 20001211
Abstract (en)
In an excavating/slewing work truck, the boom falls freely at the time of lowering operation without requiring any power but the flow rate of a pump increases excessively when the speed is balanced with other acutuators and power loss is inevitable for enhancing the operability. In order to eliminate this inconvenience, a first oil path (41) connecting a bottom side cylinder port (CB) and a tank port (T2), a second oil path (42) connecting a pump port (P2) and a rod side cylinder port (CR), and a third oil path (43) connecting a pump port (P1) and a tank port (T1) are provided, respectively, with first, second and third restrictors (61), (62) and (63) at the boom down position of a change-over valve (51) for the boom cylinder of an excavating/slewing work truck, wherein the first restrictor (61) restricts by such an amount as the work machine lowers gravitationally an the second restrictor (62) restricts by such an amount as the pressure on the boom side is not exceeded. <IMAGE>
IPC 1-7
IPC 8 full level
E02F 9/22 (2006.01); F15B 11/00 (2006.01); F15B 11/042 (2006.01); F15B 11/044 (2006.01); F15B 13/04 (2006.01)
CPC (source: EP KR US)
E02F 9/2239 (2013.01 - EP US); E02F 9/226 (2013.01 - EP US); E02F 9/2267 (2013.01 - EP US); E02F 9/2271 (2013.01 - EP US); E02F 9/2292 (2013.01 - EP US); F15B 11/00 (2013.01 - KR); F15B 11/042 (2013.01 - EP US); F15B 11/044 (2013.01 - EP US); F15B 13/0403 (2013.01 - EP US); F15B 2211/20576 (2013.01 - EP US); F15B 2211/30505 (2013.01 - EP US); F15B 2211/30515 (2013.01 - EP US); F15B 2211/30525 (2013.01 - EP US); F15B 2211/3116 (2013.01 - EP US); F15B 2211/3127 (2013.01 - EP US); F15B 2211/3138 (2013.01 - EP US); F15B 2211/324 (2013.01 - EP US); F15B 2211/329 (2013.01 - EP US); F15B 2211/351 (2013.01 - EP US); F15B 2211/353 (2013.01 - EP US); F15B 2211/50536 (2013.01 - EP US); F15B 2211/5059 (2013.01 - EP US); F15B 2211/5151 (2013.01 - EP US); F15B 2211/55 (2013.01 - EP US); F15B 2211/7053 (2013.01 - EP US); F15B 2211/7058 (2013.01 - EP US)
Designated contracting state (EPC)
AT BE CH CY DE DK ES FI FR GB GR IE IT LI LU MC NL PT SE TR
DOCDB simple family (publication)
EP 1342923 A1 20030910; EP 1342923 A4 20040310; EP 1342923 B1 20100714; AT E474142 T1 20100715; CN 1284932 C 20061115; CN 1479840 A 20040303; DE 60142577 D1 20100826; JP 2002181004 A 20020626; JP 4532725 B2 20100825; KR 100792611 B1 20080109; KR 20030064418 A 20030731; US 2004093769 A1 20040520; US 6922923 B2 20050802; WO 0248553 A1 20020620
DOCDB simple family (application)
EP 01270704 A 20011129; AT 01270704 T 20011129; CN 01820403 A 20011129; DE 60142577 T 20011129; JP 0110453 W 20011129; JP 2000375860 A 20001211; KR 20037007759 A 20030611; US 43384203 A 20031208